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The Increase in Autism Diagnoses: Two Hypotheses

A new study sheds more light on the question of what is causing the recent increase in the rate of diagnosis of autism. Professor Dorothy Bishop from the University of Oxford studied adults who were diagnosed in 1980 with a developmental language disorder. She asked the question – if these people were subjected to current diagnostic criteria for autism, how many of them would be diagnosed today as having autism? She found that 25% of them would. (Bishop 2008)

This epidemiological question has been at the center of a controversy over whether or not there is a link between vaccines (or the mercury-based preservative, thimerosal, that was previously in routine childhood vaccines) and autism. The primary evidence for this claim put forward by proponents of a link is that the number of diagnoses of autism increased dramatically at the same time that the number of vaccines routinely given to children was increasing in the 1990′s. They are calling this rise in autism an “epidemic” and argue that such an increase requires an environmental factor, which they believe is linked to vaccines.

That the number of new autism diagnoses is dramatically increasing is generally accepted and not a point of debate. The historical rate of autism is about 4 per 10,000 and the more recent estimates are in the range of 15-20 per 10,000 (30-60 per 10,000 for all pervasive developmental disorders of which autism is one type). (Rutter 2005) The controversy is about what is causing this rise in diagnoses. There are two basic hypotheses: 1) That the true incidence of autism is rising due to an environmental cause, 2) That the rise in incidence is mostly or completely an artifact of increased surveillance and broadening of the definition of autism. These two hypotheses make specific predictions, and there is much evidence to bring to bear on their predictions – this recent study only being the latest.

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Posted in: Neuroscience/Mental Health, Public Health, Vaccines

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Cell Phones and Brain Tumors

The question of whether or not there is a link between the use of mobile phones (also called cell phones) and the risk of brain tumors has been cropping up more and more frequently in the media – every time a new study or analysis comes out. This is a very important question of public health as cell phone use is becoming more common, and brain tumors are a very serious and often life-threatening category of diseases.

Of course such questions are best answered by a dispassionate, careful, and systematic look at the science – what is the plausibility of a link and what is the evidence that there actually is one. At this point we are somewhere in the middle of studying this problem. We already have substantial data, but it is conflicting and the research community is still debating on how to get more definitive data everyone can agree upon. So at present there is a variety of opinions on the matter. The consensus seems to be that cell phones probably do not cause brain tumors, but we’re not sure, there is meaningful dissent from this opinion, and so more study is needed.

There are two types of scientific studies we can do to answer this question. The first is biological and looks at the effects of radiation, and specifically the type and strength of radiation emitted by cell phones, on cells in a test tube and on animals. This will tell us if a risk from cell phones is plausible, if there is a mechanism, and what, if any, the effects are likely to be. But this kind of data will not tell us if cell phones in fact have caused or are causing brain tumors.

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Posted in: Neuroscience/Mental Health, Public Health

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On the ethics of clinical trials of homeopathy in Third World countries

ResearchBlogging.orgI’m on the record multiple times as saying that I reject the entire concept and nomenclature of “alternative medicine” as being distinct from “conventional” medicine as a false dichotomy, when in reality there should be just “medicine.” Indeed, if there is one major theme to which this blog is dedicated it’s that medicine should be as much as possible science-based, a concept that takes into account not just clinical trials, which are prone to all sorts of false-positive results in the case of modalities that have no plausibility from a scientific perspective. In essence, I advocate treating “alternative” medicine the same as “conventional” medicine subjecting it to the same scientific process to determine whether it has efficacy or not, after which medicine that is effective is retained and used and medicine that fails the test is discarded. Where it comes from, the “alternative” or the “conventional” medical realm, matters little to me. All that matters is that it is based on sound science and that it has been demonstrated to have efficacy significantly greater than that of a placebo.

Given that, you’d think I’d be all in favor of subjecting alternative medicine, be it woo or more credible, to rigorous scientific testing. In many cases, you’d be right. My sole caveat is that, when testing alt-med, priority should be given to modalities that have at least a modicum of scientific plausibility, even if a bit tenuous. Herbal remedies would thus be at the front of my line to be tested, while obvious woo whose core principle on which it is based is so utterly ridiculous and scientifically implausible (like homeopathy, for instance) would be relegated to the back of line, if it’s ever tested at all. More implausible modalities that might work (albeit by a method that has nothing to do with the “life energy” manipulation that is claimed for it) like acupuncture would be somewhere in the middle. It’s a matter of resource prioritization, in which it makes little sense to test blatant woo before more plausible therapies are examined. Indeed, it’s arguable whether blatant woo like homeopathy should even have resources wasted testing it at all, given its extreme scientific improbability. Finally, regardless of what modality is being tested in scientific and/or clinical trials, it has to be done according to the highest ethical standards, on adults fully cognizant of or able to be taught about the questions being asked, the issues involved, and the potential risks who are thus able to give truly informed consent.
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Posted in: Homeopathy, Medical Ethics, Public Health, Science and Medicine

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When impressive science fails to impress patients

One of the greatest challenges in medicine can sometimes be to convince patients that the results of scientific and medical research apply to them, or, at the very least, to explain how such results apply. One of the reasons that medicine based not on science or evidence fluorishes is because it can be so hard to explain to patients why a particular intervention is viewed as effective. My co-blogger Steve Novella wrote about some of the fallibilities of human perception that lead to perceiving correlations and treatment effectiveness where there are none. R. Robert Bausell wrote about the same thing in his recent book Snake Oil Science. While it is undoubtedly true that people tend to pay more attention to anecdotes than to studies and statistics, there is also another reason why doctors often have problems convincing patients of the value of health interventions, and that’s the difference in perception and how we value different kinds of evidence.

A couple of years ago, I came across an article that explains this gulf between how those of us trying to practice science- and evidence-based medicine perceive the world and how most human beings not trained in medicine or science perceive it. The article, which was published in 2006 in the New York Times and written by Dr. Abigail Zuker, proposed one reason why this might be, beginning with a discussion with her mother in which she tries to convince her of the benefit of exercise, even in the elderly, a concept that her mother would have none of and dismissed contemptuously:

“Studies,” she says, dripping scorn. “Don’t give me studies. Look at Tee. Look at all the exercise she did. She never stopped exercising. Look what happened to her.”

End of discussion. Tee, her old friend and contemporary, took physical fitness seriously, and wound up bedbound in a nursing home, felled by osteoporosis and strokes, while my mother, who has not broken a sweat in the last 60 years, still totters around on ever-thinning pins. So much for exercise. So much for studies. So much for modern clinical medicine, based on the randomized allocation of treatment and placebo. All that beautiful science, stymied by the single, incontrovertible, inescapable image of Tee, the one who exercised but grew hunched and crippled anyway.

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Posted in: Clinical Trials, Public Health, Science and Medicine

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The Hannah Poling case and the rebranding of autism by antivaccinationists as a mitochondrial disorder

Regular readers of this blog may have noticed that I seem to have taken on the role of the primary vaccine blogger of this little group of bloggers trying desperately to hold the forces of pseudoscience and magical thinking at bay in the face of powerful forces trying to “integrate” prescientific belief systems with science- and evidence-based medicine, a process that would be unthinkable in just about any other field of applied science, such as aeronautics or the physics used in engineering, just as creationists try to “integrate” religion with biology. Although I do have a strong interest in the antivaccination movement in general and the claim that vaccines, or the mercury in the thimerosal preservatives that was in many childhood vaccines in the U.S. until late 2001 or early 2002 (when they were taken out) are a major cause or contributor to autism, such had not been my intention. When I started here on SBM, I had intended to be a lot more diverse. Indeed, I had even had another topic entirely in mind for this week’s post, but, as happens far too often, news events have overtaken me in the form of a story that was widely reported at the end of last week. It was all over the media on Thursday evening and Friday, showing up on CNN, Larry King Live, the New York Times, and NPR. It happens to be the story of a girl from Georgia named Hannah Poling whose case before the Vaccine Injury Compensation Program (VICP), which had originally part of a much larger proceeding known as the Autism Omnibus in which nearly 5,000 parents are petitioning the VICP for compensation based on the claim that their children’s autism were caused by vaccines, was settled by the government. This settlement was based on the observation that Poling had a rare genetic mitochondrial disease that may have been exacerbated by a series of vaccines that she had, after which, among many other problems, Hannah regressed and developed some autism-like symptoms and then months later a seizure disorder. Instantly, it was being trumpeted all over the Internet, blogosphere, and media that the government had “admitted” that vaccines cause autism. One particularly excitable antivaccinationist named Kent Heckenlively (whom we’ve met before), even went so far as to foreshadow the propaganda blitz that was to come as he wrote on the antivaccine blog Age of Autism a full week before this news blitz began:

It’s official.  The sky has fallen.  The fat lady has sung.  Pigs are flying.

[...]

In a settlement, the settling party tries to admit as little as possible.  It’s like what I imagine the settlement claim against Bill Clinton in the Paula Jones case must look like.  Nowhere in the document does he admit to dropping his pants in a hotel room and asking her to kiss it.  It likely says something along the lines of he concedes they were in a hotel room together, they were alone, and something happened which formed the basis of her law suit.

But we all know what happened there.  And we know what this settlement means.

The government just dropped its pants.

One thing this shows us is just how the blogosphere can be bubbling with information that lets one predict a public relations blitz like this. The mainstream press seemed to have been totally blindsided by this story, but if reporters had only been checking the right blogs, they would have known about it a full week before, if not longer. In any case, since Thursday, there has been a very well orchestrated public relations campaign to frame this settlement as the government “admitting” that vaccines cause autism. It’s not, as I will try to explain, but framing it that ways has thus far been a very effective PR strategy for antivaccinationists. In my nearly three years of following this topic, I thought that I had never seen anything like it before.

But I had.

This case is nothing more than a demonstration that everything old is new again and that, no matter what the science says, it’s always all about the vaccines, the claims of antivaccinationists otherwise notwithstanding, as I will now show. What we are seeing now, as we did a few years ago, is the rebranding of autism as a condition in order to serve the purposes of the antivaccination movement.
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Posted in: Public Health, Science and Medicine, Science and the Media, Vaccines

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Science-Based Nutrition

One of the most successful propaganda campaigns within health care in the last few decades has been the re-branding of nutrition as “alternative” or out of the mainstream of scientific medicine. I have marveled at how successful this campaign has been, despite all the historical evidence to the contrary. I suppose this is partly a manifestation of the public’s short-term memory, but it also seems to reflect basic psychology.

Some History

There is evidence that most ancient cultures recognized the importance of diet in health. The Greeks recognized both the benefits of a varied diet and the negative health consequences of obesity, for example. But knowledge of nutrition was limited to these broad observations and was mixed with superstition and cultural beliefs.

The science of nutrition probably dates back to 1614 when scurvy (the disease that results from vitamin C deficiency) was first recognized as a dietary deficiency, one that could be cured by eating fresh fruits and vegetables. In 1747 Lind conducted what might be the first clinical trial – systematically comparing various diets for the treatment of scurvy and finding that citrus fruits were the key to treatment.

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Posted in: Herbs & Supplements, Nutrition, Public Health, Science and Medicine

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Ultrasound Screening: Misleading the Public

There is a new industry offering preventive health screening services direct to the public. A few years ago it was common to see ads for whole body CT scan screening at free-standing CT centers. That fad sort of faded away after numerous organizations pointed out that there was considerable radiation involved and the dangers outweighed any potential benefits.

Now what I most commonly see are ads for ultrasound screening. In fact, I am sick and tired of finding them in my mailbox and between the pages of my local newspaper. Ultrasound is certainly safe, with no radiation exposure. It sounds like it might be a good idea, but it isn’t.

Life Line Screening advertises itself as “America’s leading provider of quality health screenings.” They offer “4 tests in less than 1 hour – tests that can save your life.” They travel around the country, setting up their equipment in community centers, churches, and YMCAs. For $129 you get ultrasounds of your carotid arteries, your abdominal aorta, your legs, and your heel bone. They mail you your results 21 days later. (more…)

Posted in: Health Fraud, Medical Ethics, Public Health

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Iraq civilian deaths II: Summing up

Call me naive, but I did not expect the volume or the emotional depth of the responses to the Iraqi civilian death post. I thought many would respond to the new NEJMed survey as I did; wondering about the validity of the previous surveys and recognizing that they have a validity problem. And, that there is a question about what is printed in major journals, from unexpected sources. I did not mean that studies such as Lancet II not be printed. I stated that it should not have been printed in a first line journal for the general medical public. It could have been printed in a 2nd or 3rd line specialty journal where its methods and conclusions could have been debated and reforms shaped by colleagues. I find that hints and clues to errors in pseudoscientific reports mostly lie in the methods section. But questioning a study’s validity can involve more than just a knowledge of the methods and recalculation of the data. Because the “CAM” movement has redefined the borders of the playing field as well as the rules of the game, the entire environment of the scientific system surrounding implausible or unusual reports has to be examined – this goes beyond limits of methods, and includes motivations, funding, characters, and subtexts.

In developing criteria for estimating plausibility (prior probability) the most important criterion of course is consistency and consilience with established knowledge. But there are more. One can increase the effectiveness of investigation by using indicators not presently included in “Evidence Based Medicine” or in science, but that are used in criminology (previous arrests, convictions,) business (trustworthiness, profit vs loss,) and ideology and politics (elevation of the trivial, manipulation of the system; example: sectarian medicine.)

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Posted in: Medical Ethics, Politics and Regulation, Public Health

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Toxic myths about vaccines

Ever since there have been vaccines, there has been an antivaccination movement. It began shortly after Edward Jenner discovered how to use the weaker cowpox virus to induce long-lasting immunity to smallpox, there has been resistance to the concept of vaccination, a resistance that continues to this very day. Reasons for this resistance have ranged from religious, to fear of injecting foreign substances, to simple resistance to the government telling people what to do. Some fear even the infitessimally small risk that vaccines pose for the benefit of resistance to disease far more than they fear the diseases themselves, a result of the very success of modern vaccines. Of course, vaccines, like any other medical intervention, are not without risks, making it easy for them to jump on any hint of harm done by vaccines, whether real or imagined, even though vaccines are among the very safest of treatments.

One of the biggest myths that antivaccinationists believe and like to use to stoke the fear of vaccines is the concept that they are full of “toxins.” The myth that mercury in the thimerosal preservative commonly used in vaccines in the U.S. until early 2002 was a major cause of autism is simply the most recent bogeyman used to try to argue that vaccines do more harm than good, as was the scare campaign engineered in response to Andrew Wakefield’s poor science claiming a link between the MMR vaccine and autism. Now that study after study have failed to find or corroborate a link between thimerosal in vaccines or vaccines in general and autism to the point where even the most zealous of zealots are having a hard time defending the claim that mercury in vaccines cause autism any more, predictably the campaign against vaccines has fallen back on the old “toxins” myth. If you peruse antivaccinationist websites, it won’t take long to find articles claiming that vaccines are full of the most terrifying and nasty toxins. Examples in the media abound as well. For example, Jenny McCarthy, comic actress and former Playboy Playmate who has been doing the talk show and publicity circuit lately to plug her book in which she claims that vaccines caused her son’s autism and that she was able to cure it with “biomedical” interventions and diet, recently gave an interview in which she said:

What I really am is “anti-toxins” in the vaccines. I do believe that there is a correlation between vaccinations and autism. I don’t think it’s the sole cause, but I think they’re triggering–it’s triggering–autism in these kids. A really great example is…is, sometimes obesity can trigger diabetes. I do believe that vaccines can trigger autism…It’s so much more than just mercury. That is one ingredient in the recipe of autism…I’m talking about all of them. I’m calling for cleaning out the toxins. People don’t realize that there is aluminum, ether, antifreeze, still mercury, in the shots…People are afraid of secondhand smoke, but they’re OK with injecting the second worst neurotoxin on the planet in newborns.

Another example of what I sometimes call the “toxin gambit” comes from Deirdre Imus, wife of shock jock Don Imus, with both husband and wife being well-known and reliable media boosters of the claim that vaccines somehow cause autism:

So, where are the evidenced based (conflict free) studies that prove the safety of these “trace” amounts and proof that there are “no biological effects” of any amount of mercury being injected into our children and pregnant moms? Also, where are the evidence based studies proving the safety of vaccines given to pregnant moms and our children that contain other toxins such as aluminum and formaldehyde?

The most recent example of this tactic comes from an organization called Generation Rescue, which just last week ran a full-page ad in USA Today, paid for in part by Jenny McCarthy and her present boyfriend Jim Carrey:

antivaxgradvertisement.jpg

Besides being one of the most egregious examples of a post hoc ergo propter hoc fallacy that I’ve ever seen from an antivaccination site, this Generation Rescue ad demonstrates clearly a new strategy (or, more properly, a resurrection of an old technique) now that science is coming down conclusively against mercury in vaccines as a cause of autism, a strategy of propagating fear by linking vaccines with “toxins.” So what’s the real story? Are there really deadly toxins in vaccines that parents should be worried about?
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Posted in: Public Health, Science and Medicine, Science and the Media, Vaccines

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The infiltration of complementary and alternative medicine (CAM) and “integrative medicine” into academia

A few years back, my co-blogger Wally Sampson wrote a now infamous editorial entitled Why the National Center for Complementary and Alternative Medicine (NCCAM) Should Be Defunded. When I first read it, I must admit, I found it to be a bit harsh and–dare I say?–even close-minded. After all, plausibility aside, I believed at the time that the only way to demonstrate once and for all in a way that everyone would have to accept that many of these “alternative” therapies were no more effective than a placebo would be to do high-quality randomized clinical trials to test whether they worked, and NCCAM seemed to be the perfect funding agency to see that this occurred. Yes, this attitude in retrospect was quite naïve, as I have since learned the hard lesson over several years that no amount of studies will convince advocates of complimentary and alternative medicine (CAM) that their favored therapy doesn’t work, be it chelation therapy for autism or cardiovascular disease, homeopathy, reiki, or various other “energy” therapies that invoke manipulation of qi as a means of “healing,” such as acupuncture, but that is what I believed at the time.
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Posted in: Basic Science, Clinical Trials, Energy Medicine, Medical Academia, Public Health, Science and Medicine, Science and the Media

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